The present invention relates to delivery particles, particularly to particles for the delivery of laundry additives, such as perfume agents, and detergent compositions including the delivery particles, especially granular detergents.
Most consumers have come to expect scented laundry products and to expect that fabrics which have been laundered also have a pleasing fragrance. In many parts of the world handwashing is the predominant means of laundering fabrics. When handwashing soiled fabrics the user often comes in contact with the wash solution and is in close proximity to the detergent product used therein. Handwash solutions may also develop an offensive odor upon addition of soiled clothes. Therefore, it is desirable and commercially beneficial to add perfume materials to such products. Perfume additives make laundry compositions more aesthetically pleasing to the consumer, and in some cases the perfume imparts a pleasant fragrance to fabrics treated therewith. However, the amount of perfume carryover from an aqueous laundry bath onto fabrics is often marginal. Industry, therefore, has long searched for an effective perfume delivery system for use in detergent products which provides long-lasting, storage-stable fragrance to the product, as well as releases fragrance during use to mask wet solution odor and delivers fragrance to the laundered fabrics.
Further, after drying fabrics under the sun, fabrics obtain a xe2x80x9csun dried typexe2x80x9d of odor. Consumers often prefer this to a standard perfume odor. Also they often consider fabrics with these odors to be cleaner. Because consumers like the odor, they like to dry fabrics under the sun. In some countries, however, consumers cannot dry their fabrics outside because the air is not clean, or there is too much rain. As a result, they have to dry their fabrics indoors and cannot expect to enjoy this benefit of having a xe2x80x9csun-dried typexe2x80x9d of odor on their fabrics.
A detergent composition comprising a perfume which can provide a xe2x80x9csun-dried typexe2x80x9d of odor has now been found.
Laundry and other fabric care compositions which contain perfume mixed with or sprayed onto the compositions are well known from commercial practice. Because perfumes are made of a combination of volatile compounds, perfume can be continuously emitted from simple solutions and dry mixes to which the perfume has been added. Various techniques have been developed to hinder or delay the release of perfume from compositions so that they will remain aesthetically pleasing for a longer length of time. To date, however, few of the methods deliver significant fabric odor benefits after prolonged storage of the product.
Moreover, there has been a continuing search for methods and compositions which will effectively and efficiently deliver perfume from a laundry bath onto fabric surfaces. As can be seen from the following disclosures, various methods of perfume delivery have been developed involving protection of the perfume through the wash cycle, with release of the perfume onto fabrics. U.S. Pat. No. 4,096,072, Brock et al, issued Jun. 20, 1978, teaches a method for delivering fabric conditioning agents, including perfume, through the wash and dry cycle via a fatty quaternary ammonium salt. U.S. Pat. No. 4,402,856, Schnoring et al, issued Sep. 6, 1983, teaches a microencapsulation technique which involves the formulation of a shell material which will allow for diffusion of perfume out of the capsule only at certain temperatures. U.S. Pat. No. 4,152,272, Young, issued May 1, 1979, teaches incorporating perfume into waxy particles to protect the perfume through storage in dry compositions and through the laundry process. The perfume assertedly diffuses through the wax on the fabric in the dryer. U.S. Pat. No. 5,066,419, Walley et al, issued Nov. 19, 1991, teaches perfume dispersed with a water-insoluble nonpolymeric carrier material and encapsulated in a protective shell by coating with a water-insoluble friable coating material. U.S. Pat. No. 5,094,761, Trinh et al, issued Mar. 10, 1992, teaches a perfume/cyclodextrin complex protected by clay which provides perfume benefits to at least partially wetted fabrics.
Another method for delivery of perfume in the wash cycle involves combining the perfume with an emulsifier and water-soluble polymer, forming the mixture into particles, and adding them to a laundry composition, as is described in U.S. Pat. No. 4,209,417, Whyte, issued Jun. 24, 1980; U.S. Pat. No. 4,339,356, Whyte, issued Jul. 13, 1982; and U.S. Pat. No. 3,576,760, Gould et al, issued Apr. 27, 1971. However, even with the substantial work done by industry in this area, a need still exists for a simple, more efficient and effective perfume delivery system which can be mixed with laundry compositions to provide initial and lasting perfume benefits to fabrics which have been treated with the laundry product.
The perfume can also be adsorbed onto a porous carrier material, such as a polymeric material, as described in U.K. Pat. Pub. 2,066,839, Bares et al, published Jul. 15, 1981. Perfumes have also been adsorbed onto a clay or zeolite material which is then admixed into particulate detergent compositions. Generally, the preferred zeolites have been Type A or 4A Zeolites with a nominal pore size of approximately 4 Angstrom units. It is now believed that with Zeolite A or 4A, the perfume is adsorbed onto the zeolite surface with relatively little of the perfume actually absorbing into the zeolite pores. While the adsorption of perfume onto zeolite or polymeric carriers may provide some improvement over the addition of neat perfume admixed with detergent compositions, industry is still searching for improvements in the length of storage time of the laundry compositions without loss of perfume characteristics, in the intensity or amount of fragrance released during the wash process and delivered to fabrics, and in the duration of the perfume scent on the treated fabric surfaces.
Combinations of perfumes generally with larger pore size zeolites X and Y are also taught in the art. East German Patent Publication No. 248,508, published Aug. 12, 1987 relates to perfume dispensers (e.g., an air freshener) containing a faujasite-type zeolite (e.g, zeolite X and Y) loaded with perfumes. The critical molecular diameters of the perfume molecules are said to be between 2-8 Angstroms. Also, East German Patent Publication No. 137,599, published Sep. 12, 1979 teaches compositions for use in powdered washing agents to provide thermoregulated release of perfume. Zeolites A, X and Y are taught for use in these compositions. These earlier teachings are repeated in the more recently filed European applications Publication No. 535,942, published Apr. 7, 1993, and Publication No. 536,942, published Apr. 14, 1993, by Unilever PLC, and U.S. Pat. No. 5,336,665, issued Aug. 9, 1994 to Garner-Gray et al.
Effective perfume delivery compositions are taught by WO 94/28107, published Dec. 8, 1994 by The Procter and Gamble Company. These compositions comprise zeolites having pore size of at least 6 Angstroms (e.g., Zeolite X or Y), perfume releaseably incorporated in the pores of the zeolite, and a matrix coated on the perfumed zeolite, the matrix comprising a water-soluble (wash removable) composition comprising from 0% to about 80%, by weight, of at least one solid polyol containing more than 3 hydroxyl moieties and from about 20% to about 100%, by weight, of a fluid diol or polyol, in which the perfume is substantially insoluble and in which the solid polyol is substantially soluble.
Other perfume delivery systems are taught by WO 97/34982 and WO 98/41607, published by The Procter and Gamble. WO 97/34982 discloses particles comprising perfume loaded zeolite and a release barrier, which is an agent derived from a wax and having a size (i.e., a cross-sectional area) larger than the size of the pore openings of the zeolite carrier. WO 98/41607 discloses glassy particles comprising agents useful for laundry or cleaning compositions and a glass derived from one or more of at least partially-water-soluble hydroxylic compounds. A preferred agent is a perfume in a zeolite carrier.
Another problem that may occur in providing perfumed products is the excessive odor intensity associated with the products. A need therefore exists for a perfume delivery system which provides satisfactory perfume odor during use and thereafter from the dry laundered fabric, but which also provides prolonged storage benefits and reduced product odor intensity.
By the present invention it has now been discovered that perfume loaded into porous carriers such as zeolite particles, can be effectively protected from premature release of perfume by coating said loaded carrier particles with a hydrophobic oil and thereafter encapsulating the oil-coated perfume-loaded carrier particles with a water-soluble or water-dispersible, but oil-insoluble, material, such as starch or modified starch. The porous carrier may be selected to be substantive to fabrics to be able to deposit enough perfume on the fabrics to deliver a noticeable odor benefit even after the fabrics are dry.
The present invention solves the long-standing need for a simple, effective, storage-stable perfume delivery system which provides consumer-noticeable odor benefits during and after the laundering process, and which has reduced product odor during storage of the composition. In particular, fabrics treated by the present perfume delivery system have higher scent intensity and remain scented for longer periods of time after laundering and drying.
The present invention also provides a delivery system for other additives, which are desirably protected from release until the product comprising the additive is exposed to a wet or moist environment.
The present invention relates to a delivery system for additives, which are incorporated in a variety of consumer products, including detergents and cleaning compositions, room deodorizers, insecticidal compositions, carpet cleaners and deodorizers wherein the additive is protected from release until exposed to a wet or moist environment. Specifically, the present additive delivery system is a particle comprising a core of a porous carrier material containing an additive, such as a perfume, in its pores; a first coating of a hydrophobic oil encapsulating said core, and a second coating of a water-soluble or water ispersible, but oil-insoluble, material, such as starch or modified starch, encapsulating the hydrophobic-oil coated core. The present delivery particle can be used to deliver laundry and cleaning agents either to or through the wash cycle. A laundry additive delivery particle according to the present invention effectively delivers perfume ingredients through the wash to a fabric surface.
In traditional perfume delivery systems more than 50% of the perfume material is xe2x80x9clostxe2x80x9d due to diffusion of the volatile perfume materials from the product or by dissolution in the wash, and is not delivered to the fabric surface. In the present invention, the coatings effectively entrap the perfume material loaded into the carrier core. Thus, the perfume material is delivered to the fabric surface at a higher rate through the wash than with traditional perfume delivery systems.
The porous carrier material is typically selected from zeolites, macroporous zeolites, amorphous silicates, crystalline nonlayer silicates, layer silicates, calcium carbonates, calcium/sodium carbonate double salts, sodium carbonates, clays, sodalites, alkali metal phosphates, chitin microbeads, carboxyalkylcelluloses, carboxyalkylstarches, cyclodextrins, porous starches, and mixtures thereof. Preferably the carrier material is a zeolites such as Zeolite X, Zeolite Y, and mixtures thereof.
Particularly preferred porous carriers are zeolite particles with a nominal pore size of at least about 6 Angstroms to effectively incorporate perfume into their pores. Without wishing to be limited by theory, it is believed that these zeolites provide a channel or cage-like structure in which the perfume molecules are trapped. Unfortunately, such perfumed zeolites are not sufficiently storage-stable for commercial use in granular fabric care products such as laundry detergents, particularly due to premature release of perfume upon moisture absorption. However, it has now been discovered that the perfume-loaded zeolite can first be coated with a hydrophobic oil to protect the zeolite particles by forming a protective barrier to entrap and maintain the perfume within the zeolite""s pores, and thereafter encapsulating the oil-coated particle with a water-soluble or water-dispersible, but oil-insoluble, material. Thus, the perfume substantially remains within the pores of the zeolite particles. It is also believed that since the perfume is incorporated into the relatively large zeolite pores, it has better perfume retention through the laundry process than other smaller pore size zeolites in which the perfume is predominately adsorbed on the zeolite surface.
The hydrophobic oil coating can be a non-perfume oil but is preferably a perfume which can be the same as or different from the perfume oil loaded into the carrier. It is believed that when the present encapsulated particle is added to water, such as during laundering, the water-soluble or water-dispersible encapsulating material dissolves and starts to release the oil coating. When this oil coating is a perfume, the perfume notes are released from the wash solution, providing the wet odor benefit . The carrier particles loaded with perfume are released in the wash solution and deposit onto fabrics. After the fabrics are dried, perfume is released from the carrier as moisture in the atmosphere displaces the perfume contained in the pores of the carrier, providing the dry odor benefit
The additive contained in the porous carrier core is preferably selected from the group consisting of perfumes, bleaches, bleach promoters, bleach activators, bleach catalysts, chelants, antiscalants, dye transfer inhibitors, photobleaches, enzymes, catalytic antibodies, brighteners, fabric-substantive dyes, antifungals, antimicrobials, insect repellents, soil release polymers, fabric softening agents, dye fixatives, pH jump systems, and mixtures thereof
The preferred laundry additive to be loaded into the porous carrier material is a perfume. Preferably, the particle core is a perfume-loaded zeolite (PLZ).
The preferred encapsulating material is a starch, modified starch or starch hydrolysate while the preferred oil coating material is a perfume oil. The external encapsulating material may further include an ingredient selected from the group consisting of plasticizers, anti-agglomeration agents, and mixtures thereof.
In a further embodiment of the present invention, a laundry or cleaning detergent composition is provided. The laundry or cleaning composition comprises from about 0.001% to about 50% by weight of the composition of the laundry additive particle as described above and from about 50% to about 99.999% by weight of the composition of laundry ingredients selected from the group consisting of detersive surfactants, builders, bleaching agents, enzymes, soil release polymers, dye transfer inhibitors, fillers and mixtures thereof. Preferably, the composition includes at least one detersive surfactant and at least one builder.
Accordingly, it is an object of the present invention to provide an additive delivery particle having a core loaded with an additive, preferably a laundry additive such as a perfume, and at least two surface coatings comprising an intermediate hydrophobic oil coating and an external encapsulating coating of a water-soluble or water-dispersible material. It is another object of the present invention to provide a laundry and cleaning composition having said laundry additive particle thereon. It is a further object of the present invention to provide a laundry additive particle which can provide improved fabric odor benefits, prolong storage life capabilities, and reduce product odor intensity. These and other objects, features and advantages of the present invention will be recognizable to one of ordinary skill in the art from the following description and the appended claims.
All percentages, ratios and proportions herein are on a weight basis unless otherwise indicated. All documents cited herein are hereby incorporated by reference.